Press the saute mode on Instant Pot. When it says hot, add 1 Tbsp of oil. Add oxtail pieces to sear, do this in batches so they sear properly. Flip to the other side to sear, about 3 minutes each side. Once all the oxtails are done searing, remove from Instant pot. In the same pot, add the spices and ginger. Saute for about 2 minutes. Pour the water in and it will sizzle. Scrape the bottom of the pot to deglaze and to get the extra flavor from searing the oxtail earlier. Add the oxtail pieces back in along with the onion. Add seasonings and stir to mix. Turn off the saute mode and close the lid and press the pressure cooker button and set to high pressure. Set the time to 45 minutes. Make sure steam release handle is sealed
It will take about 10 minutes or so for Instant Pot to pressurize and then the timer will start after that
Once the cooking time is done, do natural release. Let the float valve comes down on its own, which may take 20 minutes or so. Once the valve is down, open the lid. Remove from Instant Pot. Scoop up any visible scums if you spot any. The soup isn't as cloudy as I thought it would be. Discard the spice packet and cinnamon stick. Scoop up any extra visible fat on top
Have a taste and add more seasoning to your taste if needed and keep warm for however long you need it to before serving.
Preparing noodles and bok choy:
Cook the noodles in hot boiling water until it's soft. It shouldn't take long since we've soaked them, about 5 minutes or so. Drain and refresh with running water. Toss with about 1 tsp of oil to prevent sticking together, but this step is optional.
Assembling and serving:
Portion the hor fun noodles into an individual serving bowl. You can serve the oxtail whole or shred the meat. The meat is so soft anyway it just falls off the bone. Divide the oxtail into individual bowl. Top with some bean sprouts and steamed bok choy and then ladle the soup generously over the noodles. Garnish with fresh cilantro leaves and chili if using. Serve immediately
Bring a medium pot of water to a boil and then blanch the bok choy until they are soft but still have that crunch and refresh with water to preserve that bright green colors. Set aside
For non-instant pot method, using slow cooker:
Follow step 1 on the very top until searing the meat and sauteing the spices .Transfer to slow cooker. Add onion and set slow cooker on low for 4 hours, 6 hours if you can if you have large pieces of oxtail. Add seasonings at the end of cooking. Scoop up any visible scums. Proceed to assemble and serving above